December weather forecastWestport, CA

December

Weather in December

December, the first month of the winter in Westport, is still a cool month, with an average temperature varying between 54.3°F (12.4°C) and 46.2°F (7.9°C).

Temperature

During February and December, Westport experiences its lowest temperatures, averaging a high-temperature of 54.3°F (12.4°C).

Humidity

The average relative humidity in December is 76%.

Rainfall

The month with the most rainfall is December, when the rain falls for 10.4 days and typically aggregates up to 1.77" (45mm) of precipitation.

Snowfall

In Westport, snow does not fall in January, March through December.

Daylight

With an average of 9h and 24min of daylight, December has the shortest days of the year.
On the first day of the month, sunrise is at 7:17 am and sunset at 4:51 pm. On the last day of December, sunrise is at 7:35 am and sunset at 5:01 pm PST.

Sunshine

The month with the least sunshine is December, with an average of 5.5h of sunshine.

UV index

January, February, November and December, with an average maximum UV index of 3, are months with the lowest UV index. A UV Index value of 3 to 5 symbolizes a moderate threat to health from unprotected exposure to Sun's UV rays for the ordinary person.
Note: The UV index of 3 during December translates into the following guidance:
Exercise prevention - Protecting skin and eyes from harm is required. UV radiation is strongest from the Sun during midday; protect yourself by staying in shaded areas. On bright days sunglasses that block both UVA and UVB rays should be worn. A hat with a wide brim is extremely helpful, as it can prevent roughly 50% of UV radiation from reaching the eyes.
Updated: Aug 20, 2024
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate

Frequently asked questions

In Westport, the coldest period comes during February and December, when the average high-temperature touches 54.3°F (12.4°C).

The high-temperature, in December, in Westport, records 54.3°F (12.4°C), while the low-temperature is 46.2°F (7.9°C).

In Westport, the average relative humidity in December is 76%.

The month with the most rainfall is December, when the rain falls for 10.4 days and typically aggregates up to 1.77" (45mm) of precipitation.

In December, the rain falls for 10.4 days. Throughout December, 1.77" (45mm) of precipitation is accumulated.

In Westport, snow does not fall in January, March through December.

With an average of 9h and 24min of daylight, December has the shortest days of the year.

In December, the average day length is 9h and 25min.

In December, on the first day of the month, sunrise is at 7:17 am and sunset at 4:51 pm. On the last day of the month, sunrise is at 7:35 am and sunset at 5:01 pm PST.

With an average of 5.5h of sunshine, December has the least sunshine of the year.

The average sunshine duration in December is 5.5h.

January, February, November and December, with an average maximum UV index of 3, are months with the lowest UV index.

In December, the average daily maximum UV index is 3. A UV Index of 3 to 5 symbolizes a medium health risk from exposure to the Sun's UV radiation.
Average high temperature
Average low temperature
Average pressure
Average wind speed
Average max. wind speed
Average wind speed gusts
Average humidity
Average rainfall
Average rainfall days
Average snowfall
Average snowfall days
Average daylight
Average sunshine
Average sunshine days
Average UV index
Average cloud cover
Average visibility

Average temperature in December
Westport, CA

  • Average high temperature in December: 54.3°F

The warmest month (with the highest average high temperature) is September (67.5°F).
The months with the lowest average high temperature are February and December (54.3°F).

  • Average low temperature in December: 46.2°F

The month with the highest average low temperature is August (55°F).
The coldest month (with the lowest average low temperature) is February (45.5°F).

Average pressure in December
Westport, CA

  • Average pressure in December: 30.1"Hg

The month with the highest atmospheric pressure is January (30.13"Hg).
The month with the lowest atmospheric pressure is August (29.93"Hg).

Average wind speed in December
Westport, CA

  • Average wind speed in December: 8.8mph

The windiest month (with the highest average wind speed) is June (10.9mph).
The calmest month (with the lowest average wind speed) is August (7.8mph).

Average humidity in December
Westport, CA

  • Average humidity in December: 76%

The months with the highest relative humidity are March, May and August (80%).
The month with the lowest relative humidity is October (75%).

Average rainfall in December
Westport, CA

  • Average rainfall in December: 1.77"

The wettest month (with the highest rainfall) is December (1.77").
The driest months (with the least rainfall) are June, July and August (0.08").

Average rainfall days in December
Westport, CA

  • Average rainfall days in December: 10.4 days

The month with the highest number of rainy days is March (11.4 days).
The months with the least rainy days are June and August (1.8 days).

Average snowfall in December
Westport, CA

  • Average snowfall in December: 0"

The month with the highest snowfall is February (0.04").
The months with the least snowfall are January, March, April, May, June, July, August, September, October, November and December (0").

Average snowfall days in December
Westport, CA

  • Average snowfall days in December: 0 days

The month with the highest number of snowfall days is February (0.1 days).
The months with the least snowfall days are January, March, April, May, June, July, August, September, October, November and December (0 days).

Average daylight in December /
Average sunshine in December
Westport, CA

  • Average daylight in December: 9h and 24min

The month with the longest days is June (Average daylight: 14h and 54min).
The month with the shortest days is December (Average daylight: 9h and 24min).

  • Average sunshine in December: 5h and 30min

The months with the most sunshine are July and August (Average sunshine: 11h and 48min).
The month with the least sunshine is December (Average sunshine: 5h and 30min).

Average sunshine days in December
Westport, CA

  • Average sunshine days in December: 19.7 days

The month with the most sunshine days is July (28.2 days).
The month with the least sunshine days is March (18.4 days).

Average UV index in December
Westport, CA

  • Average UV index in December: 3

The months with the highest UV index are June, July and August (UV index 5).
The months with the lowest UV index are January, February, November and December (UV index 3).

Average cloud cover in December
Westport, CA

  • Average cloud cover in December: 39

The month with the most cloud cover is March (Cloud cover 41).
The month with the least cloud cover is July (Cloud cover 10).

Average visibility in December
Westport, CA

  • Average visibility in December: 6mi

The months with the highest visibility are January, February, March, April, May, June, July, August, September, October, November and December (6mi).
The months with the lowest visibility are January, February, March, April, May, June, July, August, September, October, November and December (6mi).